R100 Camshaft removal

Hi All,
I tried a search but can't seem to find what I am looking for:
The bike: 1982 R100RT
When deciding to do a timing chain/tensioner replacement I got over zealous and removed the crank AND cam sprocket before realizing everything I read says the cam sprocket can not be put on without removing the cam. Not a huge deal, but I read in my shop manual the transmission, clutch and flywheel has to be removed--but it does not indicate why....
Once the lifters are removed and the cam flange on the front is removed will the cam not slip out and then slip back in later? What is going on on the back end--the oil pump end--that requires getting the flywheel off? Is it an impossible alignment issue with the pump?
And yes, I know the cam sprocket it rarely very worn but at 150K plus miles and a bike with almost ALL original parts I thought she deserved both sprockets.
Thanks,
Larry

Larry -

Welcome to the forum! I really don't have much experience with going this deep into an engine. Not sure which specific information you've read, but I just went through Snowbum's article on replacing a timing chain here:

http://bmwmotorcycletech.info/timingchain.htm

Near the end, he does state that the "proper" way to install the cam sprocket is with the cam out of the engine. I guess by that, he means there are other ways which might be improper and might result in not being able to set up the proper end float.

As for why it's suggested that you have to get to the rear side of the cam to remove it (and the reinstall it), are there any woodruff keys on the rear end that you can't see/align unless you are behind the flywheel?

I don't recall anything specific about this issue on the forum. In Snowbum's link, he does reference Brook's thread/website where he documented replacing a timing chain on an R75/6. Brook might have more details that would be helpful:

http://brook.reams.me/bmw-motorcyle...iming-chain-crankshaft-sprocket-nose-bearing/

As for searching, read this thread I put together:

http://forums.bmwmoa.org/showthread.php?77843-Tips-on-Searching-the-MOA-Forum

The use of the google site search is actually pretty helpful.

Thanks,
I have read snowbum's article. It trends toward--'don't remove the cam sprocket, it's probably fine, but if you do, pull the cam'. As you suggest, I am guessing there is something at the back end, but I am hoping for someone with direct knowledge of what the deal is. I am amazed I can't find a video or something of someone removing the cam. I don't want to pull it all apart to discover it can be done from the front with a little patience and finesse.

I have compiled videos that I've been able to find, mostly on youtube, and most by Chris Harris...he takes some getting use to though!

http://forums.bmwmoa.org/showthread.php?75891-On-line-Maintenance-Videos-Mostly-Chris-Harris

I haven't searched for everything on youtube, but maybe there are some hidden gems out there.

What part of the country are you located in? Tom Cutter is in eastern PA and Ted Porter is in northern CA. They might have some input. And have you looked at the Anonymous book for people near you who might have a range of experience with engine work?

cam key

Hi , heres my take ,the cam wont pull out with the sprocket and flange removed, there is a woodruff key at the rear which drives the oil pump inner rotor the g/box clutch and flywheel, oil pump cover has to be removed to remove the key before the cam can be pulled out, I would remove the oil pan and brace the cam some way replace the flange and heat the sprocket and tap until the end play is correct replace the chain. the later airheads not sure of the year have a flat drive which locates in a hole in the oil pump drive no key so can be removed and replaced without problems , hope this assists jimmy

jimwjarmour said:

Hi , heres my take ,the cam wont pull out with the sprocket and flange removed, there is a woodruff key at the rear which drives the oil pump inner rotor the g/box clutch and flywheel, oil pump cover has to be removed to remove the key before the cam can be pulled out, I would remove the oil pan and brace the cam some way replace the flange and heat the sprocket and tap until the end play is correct replace the chain. the later airheads not sure of the year have a flat drive which locates in a hole in the oil pump drive no key so can be removed and replaced without problems , hope this assists jimmy

Click to expand...

Real OEM shows a flat on the back end of the cam for an '82 R100. So he might have lucked out. HOWEVER, this needs to be verified with somebody who actually knows because parts fiche drawings can be weird.

Good info. Thanks.
I have now read references to both styles: circular with woodruff key and a flattened end. (And the Clymer says the crank drives the oil pump--WRONG!!)
So, anyone out there with a 1982 who can provide light on which cam it is? Lets hope
And I understand why the lifters have to be out for the cam to slide out but do the connecting rods really have to be out?
Or--even better--has anyone boiled the sprocket in oil--cooled the end of the cam with spray--and it just slipped on???????? That is my plan with the crank sprocket but that is indicated as a successful way to do that in my reading.
Thanks again--keep the info coming!
Larry

515PHOTO said:

Or--even better--has anyone boiled the sprocket in oil--cooled the end of the cam with spray--and it just slipped on????????

Click to expand...

That is my understanding how you get these sprockets on. Certainly pounding them on or trying to press them on is a no-no.

515PHOTO said:

Good info. Thanks.
I have now read references to both styles: circular with woodruff key and a flattened end. (And the Clymer says the crank drives the oil pump--WRONG!!)
So, anyone out there with a 1982 who can provide light on which cam it is? Lets hope
And I understand why the lifters have to be out for the cam to slide out but do the connecting rods really have to be out?
Or--even better--has anyone boiled the sprocket in oil--cooled the end of the cam with spray--and it just slipped on???????? That is my plan with the crank sprocket but that is indicated as a successful way to do that in my reading.
Thanks again--keep the info coming!
Larry

Click to expand...

Larry, According to this thread the new style camshaft with two parallel flats and no woodruff key to drive the oil pump began in September of 1978, for the 1979 model year. That means that you can pull your camshaft without tearing down the other end of the engine to access the oil pump.

People will tell you that you can heat the new cam sprocket and chill the end of the cam, and the new sprocket will just glide into position. I will go on record stating that this is a total fantasy! You should plan on removing the camshaft from the engine.

First of all, once the old sprocket is removed, the camshaft has a lot of end-float. I found that on my 1974 R90/6, the cam would move in/out by .046" with the old sprocket off. When I was still under the misconception that I could thermally fit the new sprocket, I removed the oil pan and used a wooden wedge under the edge of a cam lobe to hold the shaft forward. I then made four attempts to heat the sprocket while chilling the camshaft and slipping the new sprocket into position. The idea was to slide it on until it stopped against a couple pieces of .004" shim stock. I had the engine directly beside the oven. I used more heat with each successive try. On the final attempt, I had the sprocket at 390°F (pushing the limit of acceptable temperature without damage to the part). It did not even come close to slipping quickly into place. It always seized a short distance onto the shaft. I did not try any hammer tapping while the cam was still in the engine.

In the FWIW category, I did measure the sprocket I.D.'s and the shaft O.D. before I started. The new cam sprocket had a slightly smaller internal bore diameter than the original one, and this may have been why I did not succeed.

By my measurements, the old cam sprocket had .0007" interference, and the new one was marginally tighter at .0010" interference. Unlike the crank sprocket, which can be pressed into place (and I had to do that even though I heated the crank sprocket and chilled the end of the crank), there is no way I see to install the cam sprocket except to get it hot enough (big enough) to slip on easily, or remove the cam. With the cam out of the engine, you can either use a press, or a hammer and driver.



This worked for me. I put the cam into the freezer for an hour or two, and the sprocket went into the oven till it was at 400°F. Then my wife held the camshaft vertically, with its oil pump end resting against my trusty tree stump. I started the sprocket onto the cam, slipped the pipe over the quill, and drove the sprocket home with the hammer.

I didn't have to drive it very hard, but there was no way it was just going to slide onto the shaft due to thermal expansion / contraction. The plan was for my wife to also hold a piece of .004" shim stock in the right spot to set end-play, but that was expecting too much from a non mechanic. I lightly drove the sprocket all the way on, then used my Cycleworks puller to pull on it till it just lightly popped. My lucky day -- the .004" feeler gage was a snug, sliding fit. Here you can see the gauge levitating.



You can also see the little key that made it necessary for me to disembowel the back of the engine to remove the cam. Your engine should have two flats to engage and drive the oil pump rotor, and no stupid key -- good idea!

Good luck with your adventure, but plan on pulling the cam (no, your con rods do not need to come out in order to do this).

Ray

Wow--great info.
And............ I have the cam out without removing the transmission!
My 1982 does indeed have the flattened oil pump end.
Now, as long as I have the pistons in my hands I am wondering if I should do the rings. Another $120 is not really in the budget but they have 120K+ miles on them. I will start another thread on this question.
Thanks everyone.

I'm Changing the Cam on my 1986 R-80... How did you initially pull the Cam Sprocket/Cam Assy out of the front... Clymers says to pull the sprocket off with crow bars... (not) I tried to do this gingerly and it's not moving, so I removed the 2 bolts retaining the front Cam Bearing and tried to remove the assy.... It's in as tighter than I want to pry as well...

Also the Crank Timing Chain gear is worn... going to have to do this. ordered the "Front Set Tooling" from Cycle Works (Thanks again Bum) for $138.00 to do this.

Thanks for your initial post on the big question of your quest on finding truth about the mystery of gear box removal to get to a retainer on the oil pump on our 1980 and on Air heads!!!!

^^^ Don't use crowbars and only believe about every third paragraph in the Clymer Manual. The trick is figuring out which paragraphs are valid. The others range from ridiculous to destructive. After a while, you get the gist of it. The job is easy if you get the right tools.

Dan at CycleWorks did have a nice 3-jaw puller that worked really well on my '74 R90/6. I just looked at his site and can't find it for some reason. The jaw ends were ground thin enough to fit behind the sprocket. Here is how I used it. I had the AAU quill to protect, so the puller came with an aluminum spacer of the appropriate length. It was threaded to accept a hardened steel bolt into the end. Your bike will be a little different:









The same hardened steel bolt fits the nose of the crankshaft to protect it when pulling the bearing and sprocket there:



The crankshaft sprocket and nose bearing both come off together. The puller is friendly to the bearing, pressing only on the center race. I had a new bearing, but would not be worried over re-using the old one after using this puller (assuming the bearing was in good shape to begin with).



Just fit one of the clam-shell pieces of the crank sprocket / bearing puller:



Add the other half of the clam-shell:



Add the outer ring to keep it all engaged:





Then get out the wrenches. I could have gone upstairs and gotten some bigger wrenches that would look a little more professional, but that would have meant . . . going upstairs. I inherited these two Crescent Wrenches (capitalized because that is the actual brand name on the handle) from my wife's grandfather. Every time I use them, I feel like he is right there with me. One is a whopper -- 14". The other is only a 10 incher. They did the job just fine.





So, there's the front end all naked and bare, and ready to start going back together. This was my first time doing this, so in no way is this an expert "how-to" thread. It's just that I had searched in vain for pictures of these tools in use. I thought I'd go ahead and add mine for what it's worth.



My build thread is over on the Adventure Rider Forum. Click here if interested. Caution -- it's a pretty long and wordy thread. I called it My Barn Twins.

fxray - Thanks for the pictures and information, the area of concern for me is how does the post 1979 and later Camshafts come out via the front? Ted Porter confirmed that on these latter machines (after getting the Simplex Single Row Chain off) is to remove the 2 Camshaft front bearing housing bolts off and remove the Camshaft.

I see on your pictures that the Camshaft timing gear was removed by the puller and the camshaft remained in the engine.... then went to the Barns Twin Tread... and you had the camshaft removed after the Timing Gear was removed.

I am trying to remove the timing Gear and Camshaft as an assembly.... Later bikes as you pointed out don't have to have oil pump access to do this.

I assume one uses the same puller from Cycleworks ( awaiting the tooling still) to pull the whole assy out as the bearing housing has an interference fit with the case...

Anyway, thanks for the link and pictures!!

acftfliehr,

No, the bearing puller from Cycle Works that I showed in a picture above will not remove the cam and sprocket together as a unit from the crankcase. The puller jaws grab the back edges of the sprocket and the puller's center bolt pushes against the end of the camshaft (via a spacer). Picture that in your mind and you will see that the puller can only remove the sprocket from the camshaft.

If you have removed the valve lifters from your engine, and have removed the two bolts that attach the bearing flange to the front of the crankcase, you should be able to slip the camshaft and sprocket out of the engine as an assembly if that is what you are trying to accomplish.

The reason that I pulled the sprocket and then later pulled the camshaft is because I had been told (erroneously) that I would be able to heat the new camshaft sprocket and slip it into place on the nose of the camshaft without removing the camshaft from the crankcase. I found that to not be true. Even heated to nearly 400°F, the sprocket did not expand enough to slip onto the end of the camshaft. That is why I ended up pulling the camshaft to install the sprocket.

FxRay..

I have removed the valve lifters from the engine, and have removed the two bolts that attach the bearing flange to the front of the crankcase,

But using the "Clymer" way of Prying "Gently" I can't the bloody the camshaft and sprocket out of the engine as an assembly.....

I think I will call the guys at CycleWorks and see if what they're sending me will work... and if this a issue on the 179 and later bikes... The interference fit of the front Camshaft bearing and engine case (if this is what's holding it up).

Again thanks for the help and suggestions even the Bike is a bit older in config the pictures show me how to pull the Crank Sprocket off when the tooling arrives...

O.K., acftfliehr. Good luck resolving this, and please let us know what you find out.

Succsess



Slide Hammer accomplished!! It didn't take much at all but it was a lot better than the Clymer "Prying" method.

I'm going to take the assembly to Ted Porter to have his machine shop swap out the timing gear and forward bearing..

I am glad to see fxray posting here in the Airheads section. As you can already tell his illustrated discussions are very informative.

Elsewhere in the Airhead section of Olds Cool on the Advrider.com website is an extensive, illustrated discussion of fxray's work
on his airhead bikes. One can easily while away a number of hours reading the discussion. I found this to be quite worthwhile. Link below (note this the same as fxray gave a few posts up) -

http://advrider.com/index.php?threads/my-barn-twins.1046332/